Piston



Oct. 21, 1930. w HILDQRF ET AL 1,779,166

PISTON Filed June is, 1928 A'II'TOIRNEYS Patented Oct. .21, 1 930 oi-"Fi es.

WALTER JG.-

Annmarie ssnennnr, on ansnie, ,m rc -rmnn nssimnons m- REO MOTOR CAR COMPANY, or LANSING, MIGHIIGAJDI',IAI,GORPOMTIQNDE'IHCHIGWN" Applicat on med June 18,

o vantages result from the use of aluminum pistons but several disadvantages have been encountered and are recognlzed 1n the use of pistons formed of this or anyother relatively soft metal. Aluminum pistons, especially is when used in high speed high compression motors have been ob ectionable in that the ring grooves rapidly become worn and as a consequence enlarged thereby permitting undue movement of the piston rings therein.

, at This not only results in the production of noise but many other obvious objections.v

It is therefore, one of the primary objects of this invention to provide means for reinforcing or strengtheningthe ring grooves '25 of the piston by means of members located therein formed of a material having greater wear resisting properties than the material of which the piston is made. Thus the Wear occasioned by the relative movement of the piston ring with respect to the walls of the groove therefor is sustained by this material having greater wear resisting properties whereupon enlargement of the ring grooves is prevented and the resulting objections elim- 35 inated. Furthermore, by making the total amount of this material'having greater wear resisting properties relatlvely small as compared to the total amount of material ofwhich the piston is made, the weight of the 46 piston is not unduly increased.

The several objects, advantages and novel details of construction of this invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings,

wherein Figure 1 is a sectional elevational view of a piston constructed in accordance with our invention. Figure 2 is a top plan view thereof, and

ie zaf ls erm no. 286,424.

minuin or the like f is'e'ustom'ary,- in -piston eonstructions, a plurality of piston ring grooves I3 are cut or otherwiseiformedri n the wal l ll' of the 'oisto'n. fInfpractieei't-has 65 been found, that these' ring: greeves beceme enlarged re ason of". Weax" ee'casio'ned to the" top and bottom"wallsl l tliereef and it is for" the purpose of eliminatingthis disadvantagie and objection that the present invention was developed- I y V- v, H To this end wepropose casting' or otherwise integrally associating" a plurality of reinforcing elements 15 with the wall I oftliepistm when the l atter is' cast? These 're'in'forcing-el'e-- firents- 1i5'r3f18 preferably in "tlidftrMof elbngated pin-like members andare foriiredfof afmaterial possessing gre'ater wear resisting properties than the material of whieh the g Qi s o med h e f n l n mas pji tamer be i lf 'i w round cross section, asfi lilustlfafied, 'f rithey. may beofany preferred-of desired cross sectional. and longitudinal configurationffHbW' ever, "itljhas been found that in practice pin like membe of the" type flier'ein illustrated are ent'i satisfactory;

.qon nientf .inetliod, of properly poor timing the reinforcing members {-15, .d'uring thepastingzof the pisten consists; passing t e e ired mbew 7 mQ 9 -d ments ,threughsuitabl'y positioned; a entures in. {apositioniiigfixturei 1i6 Wh6I811p9n these I wineswor pinvlike members 15- :arehelde'in v proper spaced? nelation duringtheitime the metal fionming. theFpistori is being poured? in the mold; "After thei metal -ihns hamdmie'al'lbhe reinforcing elements .1 5 are efleclt 'iniiegraiv ly cwst" on; associated therewith"; The 'upper 1 so a protruding ends thereof, as illustrated in Figure may then be cut off.

These reinforcing members 15 extend longitudinally of the piston and through the wall of the piston in which the ring grooves 13 are to be cut. Vhen these grooves are subsequently cut or formed in the piston in any desired or preferred manner the cut is made through the reinforcing members 15 so that the cut ends of these members lie in the planes of the walls 14 of the ring grooves and the combined cross sectional areas of the plurality of members 15 constitute a large proportion of the areas of the upper and lower walls 14 of these grooves. As a consequence of this the walls 14 of the ring grooves are reinforced and strengthened and owing to the greater wear resisting properties of the reinforcing members 15 undue wear to the ring grooves is prevented or minimized. The presence of these members 15 in the wall 11 of the piston will obviously otherwise strengthen and reinforce the piston.

To those skilled in this art it will be apparent that the number, size and shape as well as the relative location of these reinforcing members 15 may be altered as found necessary or expedient. Likewise the relative properties of the materials of which the piston and reinforcing elements are made may also be altered as desired. To this end reservation is made to make such changes in many of the essential and all of the non-essential details of construction of this invention as may come within the purview of the accompanying claims.

What we claim as our invention is:

1. The combination with a piston, of members cast integral with said piston and extending longitudinally thereof inside the wall of the piston. in which the ring grooves are cut.

2. The combination with a piston formed of light relatively soft material, of members formed of a material having greater wear resisting properties cast integrally with said piston and extending longitudinally thereof inside the wall of the piston in which the ring grooves are cut.

3. The combination with an aluminum piston, of steel pin-like members cast integrally with said piston and extending longitudinally thereof through the wall of the piston in which the ring grooves are cut.

4:. In the method of manufacturing pistons, those steps which consist in embedding longitudinally extending reinforcing members inside a wall of the piston during the casting of the latter and cutting ring grooves in said wall which grooves extend through said reinforcing members.

5. The combination with a piston, of a member cast integrally therewith and arranged wholly within the wall thereof, the said member extending longitudinally of the 

